Morphologic and radiographic characterization of fibular dimelia

Fibular dimelia accompanied by complete tibial agenesis is a rare developme ntal anomaly that has been reported in the anatomic and clinical literature as both a dimelia and a diplopodia. Previous reports have offered variable descriptions of structural aberration and possible modes of altered embryo logic development. We present a clinical and radiographic history of the pr ogressive development of this anomaly, and a detailed postsurgical dissecti on and histopathologic examination. The specific mirroring of the separate components in this case has not been previously reported, and suggests that a reestablishment of limb polarity may have occurred during embryogenesis. Our detailed morphologic investigation strongly suggests a central role fo r the mesenchymal precursor from which chondro-osseous morphology subsequen tly emerges, and the relevance to establishing muscular attachments.